Jack White Posted July 21, 2008 Share Posted July 21, 2008 To clarify, there are two types of ground effect. The normal ground effect increases at low speed and high angles of attack, exactly the conditions one would find in a landing saituation. http://www.aerospaceweb.org/question/conspiracy/q0274.shtml A second factor that influences the impact of trailing vortices on an aircraft is the speed at which it travels. A common misconception about ground effect is that a "bubble" or "cushion" of air forms between the aircraft and ground that somehow prevents the aircraft from landing or even forces the plane upward away from the ground. Furthermore, many believe that the strength of this cushion grows the faster an aircraft flies when near the ground. Both of these beliefs are wrong. First of all, there is no bubble of air that pushes an aircraft away from the ground. The true cause of ground effect is the influence of the ground on the wing's angle of attack as described above. Ground effect does nothing to force an aircraft upward from the ground, it only changes the relative amount of lift and drag that a wing will generate at a given speed and angle of attack. Second, we have seen that this effect actually decreases with speed since induced drag has increasingly less influence on an aircraft the faster it flies. Ram ground effect (the other type) does increase at high speeds but only takes effect "where the wing is at an altitude of h/c=0.1 or less." http://eprints.soton.ac.uk/51083/01/51083.pdf h is the height and c is the chord or distance from the front of the wing to the back of the wing. From here http://www.757.org.uk/spec/spec1.html we can see the maximum chord of the 757 wing is 8.2 meters or almost 27 feet. This means that the plane would have to be flying with the wings at less than 3 feet off the ground for ram ground effect to have any effect. Actually less as the chord of the 757 wing decreases along its length and the average chord would be even less. So the only type of ground effect that comes into play in this situation is the normal type (there are two, normal and ram as described in the pdf linked above) and we already know that normal ground effect decreases with speed and lower angle of attack. Ground effect would definitely NOT keep a 757 from hitting the Pentagon at the speed and trajectory it is supposed to have been at on 911. Smoke and mirrors designed to confuse the unwary. What Lewis says only applies to a plane in a dive...not one flying parallel to the ground. Several Pentagon witnesses said THEY THOUGHT THE PLANE WAS COMING IN FOR A LANDING. A plane in a dive would not have clipped lightpoles. On the Pilots for Truth website, one pilot mentioned that he COULD NOT HAVE DONE the Pentagon approach because of the lift effect. I had not ever heard of GROUND LIFT EFFECT till several years ago when I looked it up and read extensively. What Lewis says DOES NOT APPLY to the Pentagon approach. Macbeth V, V. Jack Link to comment Share on other sites More sharing options...
Jack White Posted July 21, 2008 Share Posted July 21, 2008 No. Jetliners carry only enough fuel to reach their destination. No use transporting the weight of extra unneeded fuel. Not always. There is the practice of tankering, carrying extra fuel to offest the price difference at the next location. While it may not apply here (I don't know and don't really care), it is definitely not right to say they carry only enough fuel to reach their destination as that is not always true. Though 757 and 767s are designed to carry 24,000 gallons of jet fuel, a transcontinental flight as these were scheduled only requires about 10,000 gallons. Partly wrong. The 757 only holds about 11,000 gallons so it is wrong to say 757 and 767. Lewis is wrong here. The website I consulted said that both the 757 and 767 essentially have the same fuel capacity. His speculation about refueling is bs guesswork. Jack Link to comment Share on other sites More sharing options...
Craig Lamson Posted July 21, 2008 Share Posted July 21, 2008 No. Jetliners carry only enough fuel to reach their destination. No use transporting the weight of extra unneeded fuel. Not always. There is the practice of tankering, carrying extra fuel to offest the price difference at the next location. While it may not apply here (I don't know and don't really care), it is definitely not right to say they carry only enough fuel to reach their destination as that is not always true. Though 757 and 767s are designed to carry 24,000 gallons of jet fuel, a transcontinental flight as these were scheduled only requires about 10,000 gallons. Partly wrong. The 757 only holds about 11,000 gallons so it is wrong to say 757 and 767. Jack MUST be right, since ground effect lift would render high speed aircraft crashes impossible! :) :0 Link to comment Share on other sites More sharing options...
Craig Lamson Posted July 21, 2008 Share Posted July 21, 2008 No. Jetliners carry only enough fuel to reach their destination. No use transporting the weight of extra unneeded fuel. Not always. There is the practice of tankering, carrying extra fuel to offest the price difference at the next location. While it may not apply here (I don't know and don't really care), it is definitely not right to say they carry only enough fuel to reach their destination as that is not always true. Though 757 and 767s are designed to carry 24,000 gallons of jet fuel, a transcontinental flight as these were scheduled only requires about 10,000 gallons. Partly wrong. The 757 only holds about 11,000 gallons so it is wrong to say 757 and 767. Lewis is wrong here. The website I consulted said that both the 757 and 767 essentially have the same fuel capacity. His speculation about refueling is bs guesswork. Jack Actually commercial aircraft are REQUIRED by th e FAA to carry MORE that the fuel required to reach their destination. Additional fuel is added to add the additional flight time needed to reach an alternative airport if required. It is the Captain of the aircraft who decides the ultimate fuel load for any given commercial flight. Captains get really upset when they need to pull over at 35,000 feet for a bit more gas.... Link to comment Share on other sites More sharing options...
Matthew Lewis Posted July 21, 2008 Share Posted July 21, 2008 (edited) No. Jetliners carry only enough fuel to reach their destination. No use transporting the weight of extra unneeded fuel. Not always. There is the practice of tankering, carrying extra fuel to offest the price difference at the next location. While it may not apply here (I don't know and don't really care), it is definitely not right to say they carry only enough fuel to reach their destination as that is not always true. Though 757 and 767s are designed to carry 24,000 gallons of jet fuel, a transcontinental flight as these were scheduled only requires about 10,000 gallons. Partly wrong. The 757 only holds about 11,000 gallons so it is wrong to say 757 and 767. Lewis is wrong here. The website I consulted said that both the 757 and 767 essentially have the same fuel capacity. The website you consulted was wrong. From Boeing themselves (the manufacturer of the 757) 757 technical characteristics http://www.boeing.com/commercial/757family...pf_300tech.html 767 technical characteristics http://www.boeing.com/commercial/767family...pf_400prod.html His speculation about refueling is bs guesswork.Jack Tankering is a long established aviation concept that many pilots are aware of. http://www.iata.org/NR/ContentConnector/CS...on_Material.pdf page 50Fuel tankering is the practice of carrying more fuel than required for a particular sector in order to reduce the quantity of fuel loaded at the destination airport for the following sector (or sectors) http://en.wikipedia.org/wiki/Flight_planning Tankering fuel When fuel prices differ between airports, it might be worth putting in more fuel where it is cheap, even taking into account the cost of extra trip fuel needed to carry the extra weight. A flight planning system can work out how much extra fuel can profitably be carried. Note that discontinuities due to changes in flight levels can mean that a difference of as little as 100 kg (one passenger with luggage) in zero fuel weight or tankering fuel can make the difference between profit and loss. Jack would have noticed if he had bothered to respond without hostility that I admitted that it may not apply in this situation or in other words, I didn't speculate about anything. Therefore it changes nothing about how much fuel the planes would have had (again I don't know and don't care) and therefore doesn't change his point about the amount of fuel in the explosion, but still means that it is incorrect to say conclusively they "carry only enough fuel to reach their destination". You just can't stand being wrong can you? Edited July 21, 2008 by Matthew Lewis Link to comment Share on other sites More sharing options...
Craig Lamson Posted July 21, 2008 Share Posted July 21, 2008 (edited) No. Jetliners carry only enough fuel to reach their destination. No use transporting the weight of extra unneeded fuel. Not always. There is the practice of tankering, carrying extra fuel to offest the price difference at the next location. While it may not apply here (I don't know and don't really care), it is definitely not right to say they carry only enough fuel to reach their destination as that is not always true. Though 757 and 767s are designed to carry 24,000 gallons of jet fuel, a transcontinental flight as these were scheduled only requires about 10,000 gallons. Partly wrong. The 757 only holds about 11,000 gallons so it is wrong to say 757 and 767. Lewis is wrong here. The website I consulted said that both the 757 and 767 essentially have the same fuel capacity. His speculation about refueling is bs guesswork. Jack Maybe you need a better website, or maybe just quit believing everything you read with checking it for accuracy first. http://www.boeing.com/commercial/757family...pf_200tech.html Edited July 21, 2008 by Craig Lamson Link to comment Share on other sites More sharing options...
Matthew Lewis Posted July 21, 2008 Share Posted July 21, 2008 (edited) To clarify, there are two types of ground effect. The normal ground effect increases at low speed and high angles of attack, exactly the conditions one would find in a landing saituation. http://www.aerospaceweb.org/question/conspiracy/q0274.shtml A second factor that influences the impact of trailing vortices on an aircraft is the speed at which it travels. A common misconception about ground effect is that a "bubble" or "cushion" of air forms between the aircraft and ground that somehow prevents the aircraft from landing or even forces the plane upward away from the ground. Furthermore, many believe that the strength of this cushion grows the faster an aircraft flies when near the ground. Both of these beliefs are wrong. First of all, there is no bubble of air that pushes an aircraft away from the ground. The true cause of ground effect is the influence of the ground on the wing's angle of attack as described above. Ground effect does nothing to force an aircraft upward from the ground, it only changes the relative amount of lift and drag that a wing will generate at a given speed and angle of attack. Second, we have seen that this effect actually decreases with speed since induced drag has increasingly less influence on an aircraft the faster it flies. Ram ground effect (the other type) does increase at high speeds but only takes effect "where the wing is at an altitude of h/c=0.1 or less." http://eprints.soton.ac.uk/51083/01/51083.pdf h is the height and c is the chord or distance from the front of the wing to the back of the wing. From here http://www.757.org.uk/spec/spec1.html we can see the maximum chord of the 757 wing is 8.2 meters or almost 27 feet. This means that the plane would have to be flying with the wings at less than 3 feet off the ground for ram ground effect to have any effect. Actually less as the chord of the 757 wing decreases along its length and the average chord would be even less. So the only type of ground effect that comes into play in this situation is the normal type (there are two, normal and ram as described in the pdf linked above) and we already know that normal ground effect decreases with speed and lower angle of attack. Ground effect would definitely NOT keep a 757 from hitting the Pentagon at the speed and trajectory it is supposed to have been at on 911. Smoke and mirrors designed to confuse the unwary. What Lewis says only applies to a plane in a dive...not one flying parallel to the ground. Several Pentagon witnesses said THEY THOUGHT THE PLANE WAS COMING IN FOR A LANDING. A plane in a dive would not have clipped lightpoles. On the Pilots for Truth website, one pilot mentioned that he COULD NOT HAVE DONE the Pentagon approach because of the lift effect. I had not ever heard of GROUND LIFT EFFECT till several years ago when I looked it up and read extensively. What Lewis says DOES NOT APPLY to the Pentagon approach. Macbeth V, V. Jack Of course Jack, with his vast aviation and piloting experience can show exactly where what I posted (with references) was wrong. Simple fact, ground effect decreases with increased speed. Simple fact, the airplane was descending and not in a landing configuration and therefore had negative angle of attack. Simple fact, aviation literature for decades will say that ground effect decreases with increased speed. Simple fact, Jack is wrong. ETA: I like Craig Lamson's explanation better. Edited July 21, 2008 by Matthew Lewis Link to comment Share on other sites More sharing options...
Craig Lamson Posted July 21, 2008 Share Posted July 21, 2008 This line cracked me up! "And the firefighter who took us down kept saying, "Do not look down." I kept saying, "Why?" We were stepping over people. And you know when you can feel when you are stepping over people. " Yea, I'll bet this smuck had YEARS of experience "stepping over people"! Link to comment Share on other sites More sharing options...
Terry Mauro Posted July 21, 2008 Share Posted July 21, 2008 It seems that Barry Jennings didn't see dead bodies, etc. Seems that the Loose (with the truth) Change crowd decided to interpret things differently that Jennings intended. He stepped over people - not dead people, just people (probably awaiting movement to another area).Barry Jennings WITHDREW his permission for the interview to be used because they (LC) were distorting the truth! Actually in this case I'll side with Bemas and Avery he said "I could tell I was stepping over bodies" or words to that effect but now he is changing his story again. Was he intimidated as truthers claim or are his recolections of events that morning simply unreliable? ******************************************************************************** ""I could tell I was stepping over bodies" or words to that effect...' Get it completely right, or don't bring it up at all. "are his recolections of events that morning simply unreliable?" And, your speculative antics leave a lot to be desired, BTW. You're exactly what CD pegged you as, and probably worse. But, Simkin believes in allowing all "comers and players" equal opportunity to misinform and disinform the work here, in the name of "debate." Therefore, you'll obviously continue to spout your reams of incessant drivel, designed to intimidate other forum members, here. But, you don't fool me, or any of the others with your flagrantly enormous attitude and equally high opinion of yourself. Get a life! Bravo, Terry. Since Charles Drago's succinct description of Colby is now censored here, I may start quoting YOUR assessment...unless it too is censored. I have started replying to Colby using MACBETH, ACT V, SCENE V. If they censor that too, because it might corrupt the sensitivities of the students who study here (?) then we will know how far the intolerance to truth really goes. Yeah, that's the ticket...censor Shakespeare. Jack ******************************************************** "I have started replying to Colby using MACBETH, ACT V, SCENE V. If they censor that too, because it might corrupt the sensitivities of the students who study here (?) then we will know how far the intolerance to truth really goes." Or, how truly ignorant the students may be if they can allow their sensitivities to be so easily corrupted by Shakespeare. Link to comment Share on other sites More sharing options...
Evan Burton Posted July 21, 2008 Share Posted July 21, 2008 Smoke and mirrors designed to confuse the unwary. That is GOLD, Jack, absolute GOLD! You make a statement. Matt proves you in error. So you now claim "smoke & mirrors"! Gold! You just cannot admit you are wrong, can you? It DOES apply. It would NOT prevent an aircraft hitting the Pentagon. Get used to it. Link to comment Share on other sites More sharing options...
Evan Burton Posted July 21, 2008 Share Posted July 21, 2008 No. Jetliners carry only enough fuel to reach their destination. No use transporting the weight of extra unneeded fuel. Not always. There is the practice of tankering, carrying extra fuel to offest the price difference at the next location. While it may not apply here (I don't know and don't really care), it is definitely not right to say they carry only enough fuel to reach their destination as that is not always true. Though 757 and 767s are designed to carry 24,000 gallons of jet fuel, a transcontinental flight as these were scheduled only requires about 10,000 gallons. Partly wrong. The 757 only holds about 11,000 gallons so it is wrong to say 757 and 767. Lewis is wrong here. The website I consulted said that both the 757 and 767 essentially have the same fuel capacity. His speculation about refueling is bs guesswork. Jack Jack is unaware of fuel burn rates, fixed reserve, and variable reserve. I'll get some 767 pilots I know to calculate what a nominal fuel load should have been; I don't have the figures to hand in order to calculate it. Link to comment Share on other sites More sharing options...
Jack White Posted July 21, 2008 Share Posted July 21, 2008 This one is really strange...aluminum vs steel...and aluminum wins.Jack Through two steel walls and a steel core...and emerges unscathed, WHATEVER it is. Link to comment Share on other sites More sharing options...
Jack White Posted July 22, 2008 Share Posted July 22, 2008 This is the strangest event of all, SINCE IT IS IMPOSSIBLE according to laws of physics. Planes CRASH into steel buildings; they do not MELT into them. Am I wrong? This is the event that gives rise to NO PLANE theories, since it is impossible for a REAL airplane to do this. Untruthers here will come up with something, however, like Jack does not understand photogrammetry...yeah, that's the ticket. Jack is misinterpreting the photo because he is not an official photoanalyst and just doesn't know how airplanes crash; he probably has never seen a plane crash, much less one hitting an all steel wall...yeah, that's the ticket! Jack Link to comment Share on other sites More sharing options...
Len Colby Posted July 22, 2008 Share Posted July 22, 2008 Much as it is tempting to respond in kind I won’t debase the forum by stooping to your level. I am not at all surprised you identify with Drago you are “flour from the same sack” as they say in Brazil – you inability to make a cogent argument in favor of your position is more than made up for by your vituperative tendency to insult and attack those who hold opposing viewpoints. How ironic that Jack who continuously complains of such attacks although he is rarely a victim of them applauded you. It seems that Barry Jennings didn't see dead bodies, etc. Seems that the Loose (with the truth) Change crowd decided to interpret things differently that Jennings intended. He stepped over people - not dead people, just people (probably awaiting movement to another area).Barry Jennings WITHDREW his permission for the interview to be used because they (LC) were distorting the truth! Actually in this case I'll side with Bemas and Avery he said "I could tell I was stepping over bodies" or words to that effect but now he is changing his story again. Was he intimidated as truthers claim or are his recolections of events that morning simply unreliable? ******************************************************************************** ""I could tell I was stepping over bodies" or words to that effect...' Get it completely right, or don't bring it up at all. You were obviously looking for any lame excuse to attack me, show how the differences between my paraphrasing and his exact words affected the point I was making – namely that I though Evan was wrong and the Loose Changes (in this case) had not distorted the truth and accurately quoted Jennings. "are his recolections of events that morning simply unreliable?"And, your speculative antics leave a lot to be desired, BTW. I doubt you bothered to read through the thread, in it I documented how Jennings’ story in 2007 was very different from the one he told September 11 – 18, 20001. There’s little speculation involved. The fact that he is now back tracking IMO makes him even less reliable. I can’t tell if he is intentionally making things up or if he is simply confused. In any case he seems to have a very active imagination. If you can refute the evidence I’ve presented and will present get back us. If all you have to offer is insults expect no further replies from me. You're exactly what CD pegged you as, and probably worse. But, Simkin believes in allowing all "comers and players" equal opportunity to misinform and disinform the work here, in the name of "debate." Accuracy isn’t your forte. John clearly indicated he wants posts on this forum to be accuruate, he also indicated he wanted members to avoid making personal attacks against others. Your fail on both accounts Therefore, you'll obviously continue to spout your reams of incessant drivel, designed to intimidate other forum members, here. But, you don't fool me, or any of the others with your flagrantly enormous attitude and equally high opinion of yourself. Get a life! That you resort to personal attack rather than rebut my points speaks volumes. Your mentality seems to be limited to “X, Y and Z say what I already believe they must be correct, A, B and C are sayings I don’t believe to be true they must be wrong Link to comment Share on other sites More sharing options...
Len Colby Posted July 22, 2008 Share Posted July 22, 2008 (edited) Jennings first interview can be seen here it went on the air live shortly after he was rescued: There are numerous inconsistencies with his 2007 story except for the one marked with asterisk they all were dealt with in greater detail (including citations) in a previous post 1) He said he and Hess were trapped for “an hour because they couldn`t find us” (0:50) but 2007 he said it was for “several hours” the BBC said he was trapped for “3 hours” so this is presumably what he told them. His 9/11 estimate was probably closer to the truth. Hess said they were there for “about an hour and a half” 2) He and the man who helped save him (1:15, 1:24) said it took a long time to rescue them because they (the firefighters) couldn’t find them (Jennings and Hess) in 2007 he said it was because they kept getting called away due to the collapses. 3) In 2007 Jennings said the staircase was blown out from under him but in 2001 and seemingly in 2004 (see earlier post) he and said they went down the stairs. After Jennings was interviewed the man who help rescue him spoke he mention fire fighters going up “both stair cases” (1:17) and the buildings floor plan indicate it had only 2 stairs so there wer none left to have been blown away. The man who helped the FDNY find Jennings doesn’t look like an agent of the NOW but even if one would theorize he was they would have to explain why neither Jennings or Hess mentioned this in 2001 or 2004 nor did any other account http://wtc.nist.gov/progress_report_june04/appendixl.pdf fig L-5 pg 10 Keep in mind, that the FIRST tower collapse did not significantly damage WTC7. According to NIST, only the bottom windows of the south side of the tower were damaged. BS Jack are you making stuff up now? NIST documented serious damage to the south façade. Jennings was trapped in the north side of the building and described the explosive event in WTC7 taking place before either of the two tower collapses. -all the evidence including his earlier statements indicates he was wrong about the timing. Even 2007 he indicated he could not see the towers from where he was. -He broke out a window on the north side of the building but the stairs were in the core. An examination of Jennings 2007 interview indicates he has a very active imagination. " I looked one way, the building was there, I looked the other, the building was gone” What on earth is he talking about? What building that had been visible from the north façade of the 7 WTC “was gone” anytime on 9/11 let alone before the collapse of the South Tower? “ I was trapped in there for several hours” Jennings late morning of 9/11/01 shortly after being freed “they couldn’t get to us for an hour” Michael Hess around 12:00 PMon 9/11/01 shortly after being freed “we were trapped on the eighth floor with smoke, thick smoke, all around us, for about an hour and a half. But the New York Fire Department, as terrific as they are, just came and got us out." “The firefighters came. I was going to come down on the fire hose, because I didn't want to stay there because it was too hot; they came to the window and started yelling "do not do that, it won't hold you".” His imagination went into overdrive here. Funny he didn’t mention this in his earlier accounts. I doubt the FDNY has any equipment that extends that high 7 WTC 570 feet and 47 stories tall or more than 12 feet per floor he would have been over 84 off the ground. Why would they have used such a truck if they had one on the north side of WTC 7 when there was little if any fire there? I’ve seen no photos of any such trucks operating north of WTC 7 that day. But even so how close would the hose itself had gotten to the window where he was? Jennings was (and is) a portly middle aged bureaucrat even IF a FDNY hose had gotten remotely near him the idea he would have considered trying to jump to it is absurd “And then they ran away. I didn't know what was going on. That's when the first tower fell. When they started running, the first tower started coming down. I had no way of knowing that.” Exactly he had no way of knowing at the time whether or not the other towers had collapsed. This is something he surmised later apparently sometime between his NIST (2003) interview and Loose Change (2007) interviews. I suspect seeing Loose Change affected his memory “ They kept asking "where are you? We don't know where you are?"” This corresponds with Jennings and the man who helped save him`s comments that the rescue took as long as it did because the FDNY had difficulty locating Hess and Jennings “this huge police officer came over to me and he said, "You have to run". I said, "I can't, my knees are swollen". [He said] "You'll have to get on your knees and crawl then, because we have reports of more explosions." That's when I started crawling and I saw this guy fall behind me, and his comrades came to his aid and they dragged him to safety." So he wants us to believe he was in danger and unable to walk and a “huge” cop told him to crawl and he crawled and none of the 1st responders helped him? As a NYer even though I’ve had some unplesent experience with cops I can’t believe none of the cops or firefighters would have helped him. I guess there weren't any bodies in that part of the lobby. So now I guess in addition to accusing the FDNY of complicity the conspiracists will blame the NYPD as well. EDIT Image inserted Edited July 22, 2008 by Len Colby Link to comment Share on other sites More sharing options...
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